"Opera 11.50 introduces a new and novel type of browser extension: Speed Dial extensions. Instead of handy thumbnails and links to your top sites, you can embed your Speed Dial with extensions that keep you updated - instantly - on what is happening around the Web." Other cool stuff includes more updates to the interface, password synchronisation between your Opera installations, and lots under-the-hood stuff.

where 11.10 locked up on me all the time, 11.5 has been great (been using betas and RCs). Huge improvement. Finally I'm happy using it day to day again, after 10.5 and 10.6 represented 10 months of my most visited site being broken and 11.10 locking up all the time on me